1. Field of the Invention
The invention generally relates to the handling of requests for emergency bearer services, and more particularly, to methods for requesting emergency bearer services for low priority devices, and apparatuses using the same.
2. Description of the Related Art
For a long time, various machines have been provided to make our lives more convenient in every way. Generally, machines, nowadays, are equipped with computing processors and software to accommodate us with more intelligence-based services. With the advancement of wireless communications, Machine Type Communication (MTC) has been developed to enable communications between remote machines for exchanging information and operating without human interaction. Especially for critical public infrastructures, such as water treatment facilities or bridges, MTC sensors may be employed to monitor the operation statuses of facilities and report measurement results back to control centers using various wireless access technologies, such as the Global System for Mobile communications (GSM) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for Global Evolution (EDGE) technology, Wideband Code Division Multiple Access (WCDMA) technology, Code Division Multiple Access 2000 (CDMA-2000) technology, Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) technology, Worldwide Interoperability for Microwave Access (WiMAX) technology, Long Term Evolution (LIE) technology, LTE-Advanced technology, and others.
Take the LTE technology in compliance with the 3GPP TS 24.301 specification, v10.3.0 (referred to herein as the TS 24.301 specification) as an example. A low priority indicator or MTC indicator is defined for indicating that a User Equipment (UE) has low priority for Non Access Stratum (NAS) signaling and is generally tolerant to delays. A UE may be configured for NAS signaling low priority when manufactured, and/or when accessing the service network, by Open Mobile Alliance (OMA) Device Management (DM) and/or Subscriber Identity Module/Universal Subscriber Identity Module (SIM/USIM) Over-The-Air (OTA). For a UE configured for NAS signaling low priority (also referred to as a low priority device), the RRC establishment cause used during originating an EXTENDED SERVICE REQUEST message for requesting packet services is always set to “Delay tolerant”, even if the packet services are for emergency bearer services. As a result, the emergency bearer services will not be prioritized as they should be.